OpenCV (Open Source Computer Vision) is a cross-platform library of programming functions for real time computer vision.

What is OpenCV ?

OpenCV is a library of optimized functions which are useful for Image processing, Computer Vision, etc. applications. Officially launched by Intel in 1999 and now supported by Willow Garage. Uses include: Human-Computer Interaction; Object Identification, Segmentation and Recognition; Face Recognition; Gesture Recognition; Motion Tracking, Motion Understanding; Stereo and Multi-Camera Calibration and Depth Computation; Mobile Robotics. More information may be found at wikipedia, on the project's wiki and on the project's developer site.

What Questions should have this tag ?

Questions related to usage of OpenCV libraries can bear this tag. See also what have already been asked in StackOverflow for this tag.